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Cellulose Nanocrystal-Templated Tin Dioxide Thin Films for Gas Sensing
journal contributionposted on 2020-03-04, 16:25 authored by Alesja Ivanova, Bruno Frka-Petesic, Andrej Paul, Thorsten Wagner, Askhat N. Jumabekov, Yury Vilk, Johannes Weber, Jörn Schmedt auf der Günne, Silvia Vignolini, Michael Tiemann, Dina Fattakhova-Rohlfing, Thomas Bein
Porous tin dioxide is an important low-cost semiconductor applied in electronics, gas sensors, and biosensors. Here, we present a versatile template-assisted synthesis of nanostructured tin dioxide thin films using cellulose nanocrystals (CNCs). We demonstrate that the structural features of CNC-templated tin dioxide films strongly depend on the precursor composition. The precursor properties were studied by using low-temperature nuclear magnetic resonance spectroscopy of tin tetrachloride in solution. We demonstrate that it is possible to optimize the precursor conditions to obtain homogeneous precursor mixtures and therefore highly porous thin films with pore dimensions in the range of 10–20 nm (ABET = 46–64 m2 g–1, measured on powder). Finally, by exploiting the high surface area of the material, we developed a resistive gas sensor based on CNC-templated tin dioxide. The sensor shows high sensitivity to carbon monoxide (CO) in ppm concentrations and low cross-sensitivity to humidity. Most importantly, the sensing kinetics are remarkably fast; both the response to the analyte gas and the signal decay after gas exposure occur within a few seconds, faster than in standard SnO2-based CO sensors. This is attributed to the high gas accessibility of the very thin porous film.
CNC-templated tin dioxidesurface areaprecursor conditionsCellulose Nanocrystal-Templated Tin Dioxidesignal decayprecursor mixturesCNC-templated tin dioxide filmsgas sensorcarbon monoxidepore dimensionsBETresonance spectroscopygas exposureprecursor compositionppm concentrationsSnO 2analyte gasCO sensorstin tetrachloridePorous tin dioxidegas accessibilityprecursor propertiesnanostructured tin dioxidetemplate-assisted synthesisgas sensorscellulose nanocrystals